Julio Ceasar Chavez sparring partner Jose Luis Castillo -
Chavez a legendary fighter, but his sparring partner also turned out to be an excellent LW world champ, who has some impressive names on his resume

Joe Calzaghe sparring partner Nathan Cleverly -
Its seems one undefeated Welsh hero that Bernard Hopkins wanted to avoid wasnt enough, now theres another that he alledgedly didnt seem interested in, that like the original champ, this new champ has many of the American/American based fighters not wanting to face him

Bernard Hopkins sparring partner Charles Brewer -
Excellent MW world champ Hopkins who cleaned out the MW division before running into J Taylor, had a sparring partner who managed to win a world title in the division above. Tough Philly fighters

Mike Tyson sparring partner Glen McCrory -
Youngest HW world champ ever M Tyson, the baddest man on the planet had a sparring partner in G McCrory who won a CW world title.

Which other top world champ fighters had regular sparring partners who became world champs. When I say top fighters, I mean top world champs and regular sparring partners, not one time sparring partner, or fighters that joined the same trainer when already established

Who else is there???

Did these rated top champs have fighters as regular sparring partners who became world champs
De La Hoya??? Jones Jnr??? Mayweather???